Level 3 alerts are issued when severe weather is occurring, when average temperatures have dropped to 2°C or below, and/or widespread ice and heavy snow is present.

Hazardous conditions are expected with sleet or snow possible this evening and overnight with a widespread frost forming, particularly in rural areas, along with a risk of icy patches on untreated surfaces.

Saturday is expected to be bright and frosty start but sunny for most of the day, while Sunday will remaining generally cold with overnight frosts with an increasing risk of sleet or snow at times.Overnight temperatures are not expected to rise above -3°C.A Met Office spokesperson said: “Temperatures will fall sharply after dark on Friday evening allowing icy patches to form on untreated surfaces, including footpaths and cycleways, especially where there have been wintry showers today.

“Please be aware of the potential for difficult travel conditions.”

Dr Angie Bone of Public Health England (PHE) said: “The Met Office says that many places are going to feel really cold for the next few days, which may be a bit of a shock after our recent milder weather, so it’s really important people take extra care when out and about.

“It’s worth remembering that while most outdoor slips, trips and falls in weather like this are of those who are of working age, accidents can happen to anyone.

“If you’re staying indoors have plenty of warm food and drinks to stay warm. Try to maintain indoor temperatures to at least 18°C, particularly if you are not mobile, have a long term illness or are over 65, and check weather forecasts and plan your day around them.